everything that makes the car a car. It hovers on four raycast springs, it accelerates toward a target speed rather than being pushed by a torque curve, it steers by an angle that shrinks as you go faster, it grips sideways through a friction model, gravity pulls it down or toward the surface it's driving on, which is how wall and ceiling driving works at all. What was reconstructed the complete 22 step physics frame that Epic runs 60 times a second, in order, on the physics thread Suspension | has four spring traces; force = spring term plus damper term, taken along the averaged ground normal, with a hit rejected if the surface is too steep. so its more about the ground rather than how you hit it. This is why some people noticed that bhops on the race track are kinda easier to hit that on landscape or objects Ground detection | how many wheels count as grounded (three of four, by config), the mean ground normal, incline classification, air time / ground time, landing force Drive and target speed | throttle integrates a base target speed (only while 4 wheels are down), curves shape acceleration, five separate brake cases decide how hard you slow down; a corrective force then servos your actual velocity to that target Steering and lateral friction | steer angle comes from a curve of your speed (10° standing, ~3° at full tilt), and the sideways grip is a per wheel impulse that depends on slip ratio and how many wheels are down Gravity and counter-gravity | normal gravity, plus a counter gravity term that cancels it and reapplies it into the surface when you're driving on a wall or ceiling; a quarter second "coyote time" after leaving the ground Directions | the "primary direction" the car is really travelling in, and the drive direction that forces are applied along, different when grounded, drifting, airborne, or skydiving Bonus speed and caps | how every boost source (startline, drift boost, turbo, drafting, rubberbanding, world pads) is summed into the target speed, and the speed limits that clamp it Substrate | the whole thing runs on a fixed 60 Hz physics tick, on the physics thread, exactly where Epic runs it Other the body is a grey box, so the spring geometry is derived from placeholder bounds rather than the real car mesh (this is a tracked gap, and it may explain a one off ride height drop that hasn't been fully explained yet). And Chaos, UE's physics engine, puts resting bodies to sleep, a sleeping body silently removes the forces Epic's code applies, which froze our first test run completely. ours is marked as a deviation rather than pretending it's reconstructed for now